Fix lifetime issues with va_list
The standard requires both va_start and va_end to be called from the same function. On the other hand, vsnprintf and vsprintf leave the va_list on an undefined state according to the standard, so a copy must be created before a second call to these functions.
This commit is contained in:
parent
837c9427de
commit
601a813325
37
dynstr.c
37
dynstr.c
|
@ -33,6 +33,11 @@ void dynstr_init(struct dynstr *const d)
|
|||
enum dynstr_err dynstr_vappend(struct dynstr *const d, const char *const format, va_list ap)
|
||||
{
|
||||
enum dynstr_err err = DYNSTR_OK;
|
||||
va_list apc;
|
||||
|
||||
va_copy(apc, ap);
|
||||
|
||||
{
|
||||
const size_t src_len = vsnprintf(NULL, 0, format, ap);
|
||||
const size_t new_len = d->len + src_len + 1;
|
||||
|
||||
|
@ -40,27 +45,37 @@ enum dynstr_err dynstr_vappend(struct dynstr *const d, const char *const format,
|
|||
|
||||
if (d->str)
|
||||
{
|
||||
vsprintf(d->str + d->len, format, ap);
|
||||
vsprintf(d->str + d->len, format, apc);
|
||||
d->len += src_len;
|
||||
}
|
||||
else
|
||||
{
|
||||
err = DYNSTR_ERR_ALLOC;
|
||||
}
|
||||
}
|
||||
|
||||
va_end(ap);
|
||||
va_end(apc);
|
||||
return err;
|
||||
}
|
||||
|
||||
enum dynstr_err dynstr_append(struct dynstr *const d, const char *const format, ...)
|
||||
{
|
||||
va_list ap;
|
||||
enum dynstr_err err;
|
||||
|
||||
va_start(ap, format);
|
||||
return dynstr_vappend(d, format, ap);
|
||||
err = dynstr_vappend(d, format, ap);
|
||||
va_end(ap);
|
||||
return err;
|
||||
}
|
||||
|
||||
enum dynstr_err dynstr_vprepend(struct dynstr *const d, const char *const format, va_list ap)
|
||||
{
|
||||
enum dynstr_err err = DYNSTR_OK;
|
||||
va_list apc;
|
||||
|
||||
va_copy(apc, ap);
|
||||
|
||||
{
|
||||
const size_t src_len = vsnprintf(NULL, 0, format, ap);
|
||||
const size_t new_len = d->len + src_len + 1;
|
||||
|
@ -77,29 +92,33 @@ enum dynstr_err dynstr_vprepend(struct dynstr *const d, const char *const format
|
|||
d->str[i] = d->str[j];
|
||||
}
|
||||
|
||||
vsprintf(d->str, format, ap);
|
||||
vsprintf(d->str, format, apc);
|
||||
d->str[src_len] = c;
|
||||
}
|
||||
else if (!d->len)
|
||||
{
|
||||
vsprintf(d->str + d->len, format, ap);
|
||||
vsprintf(d->str + d->len, format, apc);
|
||||
}
|
||||
else
|
||||
{
|
||||
return DYNSTR_ERR_ALLOC;
|
||||
err = DYNSTR_ERR_ALLOC;
|
||||
}
|
||||
|
||||
va_end(ap);
|
||||
d->len += src_len;
|
||||
return DYNSTR_OK;
|
||||
}
|
||||
|
||||
va_end(apc);
|
||||
return err;
|
||||
}
|
||||
|
||||
enum dynstr_err dynstr_prepend(struct dynstr *const d, const char *const format, ...)
|
||||
{
|
||||
va_list ap;
|
||||
enum dynstr_err err;
|
||||
|
||||
va_start(ap, format);
|
||||
return dynstr_vprepend(d, format, ap);
|
||||
err = dynstr_vprepend(d, format, ap);
|
||||
return err;
|
||||
}
|
||||
|
||||
enum dynstr_err dynstr_dup(struct dynstr *const dst, const struct dynstr *const src)
|
||||
|
|
Loading…
Reference in New Issue